It was hypothesized that adolescents with ADHD would show abnormalities in blood flow dynamics particularly targetting frontal brain regions while performing executive tasks. The generic brain activation of 7 male adolescents with ADHD was compared to that of 9 sex, age and IQ-matched controls while performing two higher order (cognitive) motor tasks. A stop task, requiring inhibition of a planned motor response and a timing task, requiring timing of a motor response to a sensory cue. Hyperactive adolescents showed reduced power of response in right mesial prefrontal cortex during both tasks, and in right inferior prefrontal lobe and left caudate during the stop task. The results show that 1) ADHD is associated with reduced activation of prefrontal systems responsible for higher order motor control 2) fMRI is a feasible technique for investigation of neural correlates of ADHD. Data will be discussed in light of results from a developmental study comparing blood flow dynamics in adolescents and adults using identical tasks.

Back to the top.Presentation Number SArubia0583Keywords:ADHD, impulsivity, frontal lobe, executive functio, caudate